Finite element analysis of subsurface damage of ceramic prostheses in simulated intraoral dental resurfacing

Finite element analysis (FEA) was used to investigate the stress fields and the degrees of subsurface damage of ceramic prostheses in simulated intraoral dental resurfacing operations using clinical diamond burs. A two-dimensional finite element model was established with the dental operational parameters and the material properties as input variables. This model enabled to predict the stress fields and to evaluate the depths of subsurface damage in ceramic prostheses as functions of the dental resurfacing operational conditions. The results indicate that the tensile, shear, compressive, and equivalent von Mises stresses were all centered under the diamond bur-specimen contact zone. The maximum values of these stresses were concentrated at the diamond grit exit point, decreasing with an increase in depth of cut. The predicted depths of subsurface damage increased with an increase in both the depth of cut and the maximum chip thickness, in the range of 30-140 μm. Also, the depths of subsurface damage were experimentally measured using scanning electron microscopy (SEM). The FEA predictions were found to be in agreement with the SEM experimental observations.